A NOVEL ACIDOPHILIC, THERMOPHILIC IRON AND SULFUR-OXIDIZING ARCHAEON ISOLATED FROM A HOT SPRING OF TENGCHONG, YUNNAN, CHINA

A novel thermoacidophilic iron and sulfur-oxidizing archaeon, strain YN25, was isolated from an in situ enriched acid hot spring sample collected in Yunnan, China. Cells were irregular cocci, about 0.9-1.02 mu mx1.0-1.31 mu m in the medium containing elemental sulfur and 1.5-2.22 mu mx1.8-2.54 mu m in ferrous sulfate medium. The ranges of growth and pH were 50-85 (optimum 65) and pH 1.0-6.0 (optimum 1.5-2.5). The acidophile was able to grow heterotrophically on several organic substrates, including various monosaccharides, alcohols and amino acids, though the growth on single substrate required yeast extract as growth factor. Growth occurred under aerobic conditions or via anaerobic respiration using elemental sulfur as terminal electron acceptor. Results of morphology, physiology, fatty acid analysis and analysis based on 16S rRNA gene sequence indicated that the strain YN25 should be grouped in the species Acidianus manzaensis. Bioleaching experiments indicated that this strain had excellent leaching capacity, with a copper yielding ratio up to 79.16% in 24 d. The type strain YN25 was deposited in China Center for Type Culture Collection (=CCTCCZNDX0050).